Sofa



FIG. 1 is a top perspective view of a sofa, showing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings of the sofa are for the purposes of illustrating the environment and form no part of the claimed design. 

CLAIM The ornamental design for a sofa, as shown and described. 